WASHINGTON (Reuters) - Boeing Co and Bell Helicopter, a unit of Textron Inc , have won a contract valued at $1.4 billion for 21 V-22 tiltrotor Osprey aircraft, the U.S. Defense Department said on Friday.

In a daily digest of major weapons contracts, the Pentagon said it had modified an existing advanced procurement contract with the Bell-Boeing joint venture to cover production of the additional aircraft.

The contract also includes funding for advanced procurement of materials for 22 additional aircraft to be funded in fiscal year 2014, which begins next October.

(Reporting by Andrea Shalal-Esa; Editing by Richard Chang)